Washington ? New signs emerged Wednesday that the economic rebound is sputtering. Sales of new homes hit a record low last month. And mortgage giant Freddie Mac signaled it will need more federal aid — and might never repay it.

Against that backdrop, the government is trying to prop up the housing and job markets. Federal Reserve Chairman Ben Bernanke reiterated the need to continue record-low interest rates for “an extended period.”

Bernanke told Congress that low rates will help ensure that the recovery will last and help ease the sting of high unemployment.